Monitoring chemical changes during food sterilisation using ultrahigh resolution mass spectrometry.

Sterilised food products undergo chemical changes during processing that ultimately determine the product quality. To provide detailed information on the chemistry of each stage of a pet-food sterilisation process, a laboratory-scale system was developed, which allowed sampling under the high temperatures and pressures associated with sterilisation. Products from the laboratory-scale system were representative of the factory process. Sample extracts were analysed by Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometry (FT-ICR-MS), which delivered the molecular formulae and ion intensities of the compounds present. Data were examined to determine the coverage of this method, the degree of chemical change occurring during pet food thermal processing, and the level of identification possible with FT-ICR-MS. Data visualisation and statistical analysis identified significant chemical changes in pet food as a result of processing, and allowed tentative identification of the compounds involved. Insights generated using FT-ICR-MS analysis can be confirmed and further explored using conventional, targeted analyses.

Efficacy of commercially available products against Gyrodactylus turnbulli infections on guppies Poecilia reticulata.

The demand for ornamental fish has led to a steep rise in aquaculture for the hobbyist trade, promoting the emergence, persistence and spread of various infectious diseases. Complete control of disease outbreaks with antibiotics and chemical-based medicines is rare, but plant compounds may herald potential alternatives effective against a range of pathogens. Melafix® and Pimafix® are formulated with the essential oils cajuput (Melaleuca cajuputi) and West Indian bay (Pimenta racemosa) and are marketed against bacterial and fungal infections, respectively. Previous experiments showed high efficacy of emulsified cajuput oil against gyrodactylids; the current study tested Melafix® and Pimafix® and their individual compounds against Gyrodactylus turnbulli infecting the guppies Poecilia reticulata. In particular, a combination treatment of Melafix® and Pimafix® was highly effective at reducing in vitro survival of parasites from 15 to 2 h and eradicating 95% of gyrodactylids in vivo. The unexpected high efficacy of this combination treatment is likely explained by the high content of terpenes and phenol propanoids in the cajuput and West Indian bay oils, as well as the anti-helminthic properties of the emulsifier Crovol PK 70. Hence, Melafix® and Pimafix® effectively reduce gyrodactylid burdens on fish, increasing the chances of efficient disease control in ornamental fish.